(1) The clean operating department must have an independently installed main power distribution cabinet

The main power distribution cabinet must be located in the non-clean area, mainly so that maintenance personnel can work conveniently during maintenance and repair without entering the clean area, preventing dust and bacteria from being brought into the clean area and reducing factors of cross-infection.

(2) Weak-current cabinets and strong-current cabinets shall be installed separately

(3) The capacity of the main power distribution cabinet of the clean operating department shall leave ample margin. Power consumption in the clean area and in the non-clean area shall be separated.

A hospital is a special environment, and the operating room is even more special; electric current poses a potential danger to patients, and therefore special requirements are imposed on electrical design. During surgery and under anesthesia, various electrodes, sensors, and tubes are inserted directly into the patient's body. At this point, if a leakage current of only $10mu A$ passes directly through the patient's heart, it can cause the patient to die of electric shock.

The live parts at the power source end are insulated from earth or earthed through high impedance, and the metal enclosures of electrical equipment are directly earthed. In this system, the neutral line (N) and the protective line (PE) are separated starting from the neutral point at the power source end.

[Reference] For a schematic diagram of the wiring inside the clean operating room, see 11.5. Figure 11.5　Schematic diagram of wiring inside a clean operating room

(4) The power distribution load of each operating room shall be no less than 8kW, and is used only within that operating room (excluding the power consumption of the air-conditioning and purification system equipment). If the number of electrical appliances in a certain operating room increases and the load grows, the electrical load must be recalculated. The general arrangement is as follows: shadowless lamp approximately 600W; lighting strip approximately 1.5kW; film viewing lamps 100～300W; the remainder is allocated to the wall-mounted sockets and the sockets on the pendants.

(5) The power supply lines for each operating room are laid separately from the distribution cabinet and are not shared with other operating rooms or auxiliary rooms, mainly to ensure line safety and mutual non-interference, so that when a circuit in one room fails, it will not affect the normal operation of other operating rooms.

(6) Cables (wires) are not allowed to be threaded and laid through non-metallic conduits such as PVC; they must be routed through metal conduits or cable trays, and whether metal conduits or cable trays are used, grounding must be properly completed as required.

(7) Each operating room must have an independent distribution panel (box) to supply power for that operating room. The distribution panel should be located on the wall of the outer corridor adjacent to the operating room, generally recessed (flush-mounted) into the wall; if it cannot be recessed, it may be surface-mounted, but must not obstruct traffic; if the surgical area has no outer corridor, the distribution panel (box) may also be installed on the wall of the inner corridor adjacent to the operating room, but it must be recessed into the wall, and the inside of the box should be isolated from the operating room and sealed.

(8) Access doors for electrical equipment maintenance and other maintenance doors are not allowed on the walls inside the operating room.

(9) The circuit design inside the distribution panel (box) separates each circuit according to usage requirements, and each power branch should be equipped with an air switch. Class Ⅰ operating rooms and cardiac surgery operating rooms must be equipped with isolation transformers. In each operating room, power branches such as the lighting strip, film viewing lamps, and electric doors may bypass the isolation transformer; mainly the instrument power sockets and the shadowless lamp branches must pass through the isolation transformer. The design capacity of the isolation transformer can be determined by calculating the electrical load, and is generally arranged as four output circuits: one for the shadowless lamp, two for the wall-mounted instrument sockets, and one for the multi-function pendant. Operating rooms of other classes may also be equipped with isolation transformers; if limited by investment, isolation transformers may be omitted, but an insulation leakage detection and alarm device must be installed.

(10) If the construction party has special requirements, a 380V socket may be installed in the operating room; if the operating table is of the electric type, a waterproof socket must be installed at a suitable position near the leg section of the operating table, adjacent to the table edge.

(11) Instrument power sockets in the operating room are generally located on the two walls parallel to the operating table and on the wall at the head side. Power sockets are not allowed to be installed individually; socket boxes must be installed. Each socket box generally has one two-hole single-phase socket and one to two three-hole single-phase sockets and a set of grounding terminals. The socket box must be flush-mounted (embedded installation); protrusion beyond the wall surface is not permitted, while a recess of 3～5mm is allowed. The socket box must be sealed to prevent the "breathing" phenomenon from contaminating the clean operating room. The socket box must be made of metal, and its casing must be provided with a safety grounding terminal.

[Reference] For the power distribution system, see Figures 11.6～11.8.